Hints: The Meta Puzzle

General hints for each puzzle:
This puzzle consists of 8 metapuzzles, each of which can be solved independently. However, there is one answer missing from the set of answers for each metapuzzle. Here are some hints to help you get started on each individual puzzle:
1 (BLACK SUN)
This puzzle is about the card game gin rummy. You have to solve a logic puzzle of assigning letters to cards, using the answers + card hands, example set, and example runs (the suit symbols tell you that the X of clubs is assigned the same letter as the X of diamonds for each X, and same for hearts/spades).
2 (ARGENTINA)
A potential title for this puzzle would be “Table Hopping”.
3 (ANTIGO WISCONSIN)
The second words of each of the answers have something in common that lets you reorder the answers. Start by finding that commonality.
4 (ARGUE)
Exactly half of the answers to this meta have something in common.
5 (EBB)
The answers in this meta can be divided into groups of 3.
6 (CRITIC)
There are two different systems for naming musical pitches used in this puzzle. The last step of this meta involves identifying a song (the answer is the title of the song). If you are having trouble with identification, one hint is that it’s a well-known children’s song.
7 (MACHINATE)
Start by finding a commonality among the answers. After that, each of the 6 sentences contains a sequence of 2 or more consecutive words that need to be used in some way.
8 (ALTMANN)
Exactly half of the answers to this meta have something in common.
Stuck on final step:
The last letters spell out a message.
Still stuck:
Try overlapping the bigrams.